AMY-6M - Hardware Integration Manual
UBX-17021971 – R07
Design-in
Page 35 of 57
exercised with placing the receiver in proximity to circuitry that can emit heat. The RF part of the receiver is very
sensitive to temperature and sudden changes can have an adverse impact on performance.
AMY-6M receivers are temperature sensitive devices. Avoid high temperature drift and air vents
near the receiver.
2.13
Migration considerations
The main difference between u-blox AMY-5M and u-blox AMY-6M from migration point of view is that the 3
pins EXTINT0 (PIO7), EXTINT1 (PIO8) and RXD1 (PIO4) have moved from the backup (VDD_B) domain to the IO
(VDD_IO) domain and these 3 pins now have an internal pull-up to VDD_IO.
As a consequence the following things must be considered when migrating from an existing u-blox 5 design to
u-blox 6.
The external series resistors in the USB_DM nd USB_DP lines have changed from 27 Ohm to now 22 Ohm.
Change series resistors in USB_DM and USB_DP line to 22 Ohm
The signal levels for RxD1, EXTINT0 and EXTINT1 are now related to VDD_IO and have the same input
levels as all the other IOs. There is no longer any exception for the signal input levels for RxD1, EXTINT0
or EXTINT1.
External pull-ups or pull-downs at RxD1, EXTINT0 and EXTINT1 must be removed. u-blox AMY-6M has
internal pull-ups to VDD_IO at RxD1, EXTINT0 and EXTINT1.
If RxD1, EXTINT0 and EXTINT1 were connected to GND on the u-blox 5 design, this will result in
increased current for u-blox 6 in SW backup mode. For example if VDD_IO is 3 V, RxD1 is used for
communication and EXTINT0/ EXTINT1 are connected to GND, then there will be an increased current of
about 2 * VDD_IO/pullup = 2 * 3 V / 113k Ohm = 53
μ
A.
For u-blox 5 designs with RxD1, EXTINT0 or EXTINT1 connected directly to VDD_B, the layout cannot be
directly migrated to u-blox AMY-6M and must be modified.
